projects / thirdparty / gcc.git / blame
| Commit | Line | Data |
|---|---|---|
| b8d7e076 KC |
1 | /* Multiplication two double word integers for RISC-V. |
| 2 | ||
| 83ffe9cd | 3 | Copyright (C) 2016-2023 Free Software Foundation, Inc. |
| b8d7e076 KC |
4 | |
| 5 | This file is part of GCC. | |
| 6 | ||
| 7 | GCC is free software; you can redistribute it and/or modify it under | |
| 8 | the terms of the GNU General Public License as published by the Free | |
| 9 | Software Foundation; either version 3, or (at your option) any later | |
| 10 | version. | |
| 11 | ||
| 12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
| 13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 | for more details. | |
| 16 | ||
| 17 | Under Section 7 of GPL version 3, you are granted additional | |
| 18 | permissions described in the GCC Runtime Library Exception, version | |
| 19 | 3.1, as published by the Free Software Foundation. | |
| 20 | ||
| 21 | You should have received a copy of the GNU General Public License and | |
| 22 | a copy of the GCC Runtime Library Exception along with this program; | |
| 23 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
| 24 | <http://www.gnu.org/licenses/>. */ | |
| 25 | ||
| 26 | #include "tconfig.h" | |
| 27 | #include "tsystem.h" | |
| 28 | #include "coretypes.h" | |
| 29 | #include "tm.h" | |
| 30 | #include "libgcc_tm.h" | |
| 31 | #define LIBGCC2_UNITS_PER_WORD (__riscv_xlen / 8) | |
| 32 | ||
| 33 | #include "libgcc2.h" | |
| 34 | ||
| 35 | #if __riscv_xlen == 32 | |
| 36 | /* Our RV64 64-bit routines are equivalent to our RV32 32-bit routines. */ | |
| 37 | # define __multi3 __muldi3 | |
| 38 | #endif | |
| 39 | ||
| 40 | DWtype | |
| 41 | __multi3 (DWtype u, DWtype v) | |
| 42 | { | |
| 43 | const DWunion uu = {.ll = u}; | |
| 44 | const DWunion vv = {.ll = v}; | |
| 45 | DWunion w; | |
| 46 | UWtype u_low = uu.s.low; | |
| 47 | UWtype v_low = vv.s.low; | |
| 48 | UWtype u_low_msb; | |
| 49 | UWtype w_low = 0; | |
| 50 | UWtype new_w_low; | |
| 51 | UWtype w_high = 0; | |
| 52 | UWtype w_high_tmp = 0; | |
| 53 | UWtype w_high_tmp2x; | |
| 54 | UWtype carry; | |
| 55 | ||
| 56 | /* Calculate low half part of u and v, and get a UDWtype result just like | |
| 57 | what __umulsidi3 do. */ | |
| 58 | do | |
| 59 | { | |
| 60 | new_w_low = w_low + u_low; | |
| 61 | w_high_tmp2x = w_high_tmp << 1; | |
| 62 | w_high_tmp += w_high; | |
| 63 | if (v_low & 1) | |
| 64 | { | |
| 65 | carry = new_w_low < w_low; | |
| 66 | w_low = new_w_low; | |
| 67 | w_high = carry + w_high_tmp; | |
| 68 | } | |
| 69 | u_low_msb = (u_low >> ((sizeof (UWtype) * 8) - 1)); | |
| 70 | v_low >>= 1; | |
| 71 | u_low <<= 1; | |
| 72 | w_high_tmp = u_low_msb | w_high_tmp2x; | |
| 73 | } | |
| 74 | while (v_low); | |
| 75 | ||
| 76 | w.s.low = w_low; | |
| 77 | w.s.high = w_high; | |
| 78 | ||
| 79 | if (uu.s.high) | |
| 80 | w.s.high = w.s.high + __muluw3(vv.s.low, uu.s.high); | |
| 81 | ||
| 82 | if (vv.s.high) | |
| 83 | w.s.high += __muluw3(uu.s.low, vv.s.high); | |
| 84 | ||
| 85 | return w.ll; | |
| 86 | } |